This invention relates generally to high-voltage electrical apparatus, and more particularly, to an improved gas-insulated high-voltage circuit interrupter having an improved insulating nozzle for directing the flow of gas.
High-voltage circuit-interrupters typically include a stationary contact structure and a movable contact structure which is cooperable with the stationary contact structure to transfer or interrupt electrical current therebetween. Because of the high voltages involved, each contact structure typically includes main contacts which transmit the majority of electrical current during normal operations, and arcing contacts for use during the interrupting operation. The arcing contacts are generally made of a high arc-resistant material, so that during the opening operation, where the arcing contacts part last, the arc which is drawn between the arcing contacts will not cause a deterioration of the contacts. Because of the higher voltages involved, and the need to extinguish the resultant arc between the two contact structures, means are typically included within the circuit interrupters to blast a flow of the insulating gas into the arc to cause a scattering of the ion stream occurring thereabout, extinguishing the arc more rapidly and with less damage to the various elements of a circuit interrupter. Typically, a hollow insulating nozzle is utilized for directing this flow of gas into the arc.
Because of more stringent performance specifications issued by purchasers of the equipment, manufacturers of high-voltage gas-insulated circuit interrupters are currently being required to improve the performance of their interrupters. One such improvement which is desirable is to increase the dielectric recovery characteristic of the interrupter; others are to improve the conductivity of the interrupter when in the closed position, and to increase the open circuit voltage withstand of the interrupter.